Dialysis control system



II I'II'IIIII INVENTOR$ ATTORNELE Oct. 28,1969 J. E. CARY ETAL DIALYSISCONTROL SYSTEM Filed March 15, 1966 A 0- v Ill-m: k

.m? NM 7 United States Patent r 3,474,907 DIALYSIS CONTROL SYSTEM JamesE. Cary, Edmonds, and Harvey F. Swenson, Seattle, Wash., assignors toSweden Freezer Manufacturing Co., Seattle, Wash., a corporation ofWashington Filed Mar. 15, 1966, Ser. No. 534,323 Int. Cl. B01d 13/04 US.Cl. 210-103 6 Claims ABSTRACT OF THE DISCLOSURE A bedside hemodialysisstation is provided for use in conjunction with a hemodialyzer toreceive dialysis solution from a remotely located dialysis solutionsupply means and to supply the dialysis solution to the dialylzer undercontrolled temperature and pressure conditions. The bedside dialysisstation comprises a reservoir tank adapted to be supplied with dialysissolution from a remotely located source thereof, a dialyzer supplyconduit extending from the reservoir tank and adapted to be detachablycoupled to the inlet to a dialyzer, a positive displacement pump and awaste conduit extending therefrom and adapted to be detachably connectedto the outlet from the dialyzer, suitable to temperature and pressurecontrols, and a sterilizing bypass assembly. The sterilizing bypassassembly permits sterilization of those components of the bedsidedialysis stations that come into contact with dialysis solution bysimply disconnecting the dialyzer supply conduit and waste conduit fromthe dialyzer and connecting them to the sterilizer bypass assembly,without setting ofi the temperature and pressurealarms contained withinthe bedside dialysis station.

This invention relates to apparatus for use in hemodialysis, and moreparticularly to a system for supplying a dialysis solution to a dialyzeremployed in hemodialysis and for controlling dialysis.

In recent years, artificial kidneys have been employed to treat patientswith acute renal failure and to rebaliltate patients who would otherwisedie of chronic uremia. An essential feature of an artificial kidneysystem is the dialyzer. A kill-type'dialyzer, which is generallypreferred, comprises two cellophane semipermeable envelopes throughwhich small portions of a patients blood passes in counterflow to adialysis solution passing on the outer surfaces of the cellophaneenvelopes. The dialysis solution removes Waste from the blood portionsby a permeation phenomenon. Because of the nature of hemodialysis, thepermeation process, or dialysis, must be conducted under carefullycontrolled conditions.

One of the major problems in the use of artificial kidney systems hasbeen the complexity of the apparatus associated with hemodialysistechniques. Such apparatus requires the constant attention of highlytrained personnel and further is quite bulky and expensive. Hence,dialysis control is often wasteful of the time of trained hospitalpersonnel. Furthermore, as artificial kidney systems become less complexand expensive, such systems will be frequently used by patients at homerather than at a hospital or clinic. Consequently, dialysis control mustbe pro- 3,474,907 Patented Oct. 28, 1969 vided that can be easily andsafely operated by members of a patients family at home.

It is a primary object of the invention to provide a dialysis controlsystem that is easy and safe to operate and that is suitable for useeither in the home or in a hospital or clinic. Another object is toprovide apparatus for supplying a dialysis solution to a dialyzer.

These and other objects and advantages of this invention will becomeapparent from the following description in conjunction with theaccompanying drawings, of which:

FIG. 1 is a schematic diagram of the system of this invention; and

FIG. 2 is an elevation view in cross-section of a manometer employed inthe system of this invention.

Briefly, the invention comprises a reservoir means for receiving andholding a supply of dialysis solution, supply conduit means forconnecting the reservoir to an inlet of a dialyzer, pumping means,exhaust conduit means for connecting the pumping means to an outlet tothe dialyzer, and suitable control means for controlling dialysisconditions such as the temperature and pressure of the dialysissolution.

With reference to FIG. 1, the invention comprises a reservoir tank 202with a dialysis solution inlet connected to supply conduit 94, a ventand overflow conduit 204, and a dialyzer supply conduit 206. Dialyzersupply conduit 206 connects to the inlet of a dialyzer 208 through aquick disconnect coupler 210. A waste conduit 212 connects the outlet ofdialyzer 208 to a positive displacement pumping means 214, amanually-operable shut-01f valve 216 and a flow metering means 218. Amanometer pressure sensing means 220 is connected to waste conduit 212and is adapted to stop dialysis if a negative pressure greater thanabout mm./Hg is sensed. The pressure sensing means may be a manometer asshown or may be a Bourdon tube pressure gauge.

Reservoir tank 202'is provided with a heating means 222 that is manuallyadjustable to temper the dialysis solution within reservoir tank 202 forpatient comfort, e.g. to 98 F and to hold temperature settings Within areasonable range, for example i2 F. Temperature sensor 224 and a hightemperature switch 226 are set to stop dialysis if the dialysis solutionreaches an unacceptably high temperature on the order of 106 F. Thereservoir tank 202 is also provided with a dialysis solution valvecontrol means 228 comprising a float-controlled inlet valve 230 whichprevents overfilling and a dry float switch 232 which stops dialysis ifthe quantity of dialysis solution in reservoir tank 202 falls below apredetermined minimum level.

Dialysis solution supply conduit 206 is provided with a manuallyadjustable negative pressure valve 234 to control pressure of thedialysis solution being drawn through the dialyzer 208 by pumping means214. If desired, a solenoid-operated control valve means 236 may also beprovided in conduit 206 to control dialysis solution flow to thedialyzer 208.

Waste conduit means 212 connects to the outlet to dialyzer 208 through aquick disconnect coupler 238. A sterilzing connector 240 is provided andadapted to receive couplers 210 and 238 to bypass dialyzer 208 when thebedside station is to be sterilized. Connector 240 includes a sterilizeswitch means 242 which is actuated when couplers 210 and 238 areattached to connector 240 as indicated by broken lines in FIG. 1 andwhich shuts off control circuitry associated with manometer 220, hightemperature switch 226, and alters circuitry 241 associated with floatmeans 228 so that high temperature sterilizing water can be drawnthrough the bedside station by pumping means 214 without automaticallyshutting down pumping means 214. If high temperature sterilizing wateris inadvertently passed to the bedside station without connectingcouplers 210 and 238 to bypass dialyzer 208, high temperature switch 226would automatically shut off pumping means 214 and closesolenoid-operated control valve means 236 (if provided) to stopdialysis.

The connecting tube 244 for the manometer sensing means 220 isdisconnected from waste conduit 212 at a port in coupler 238 and thenthis port is sealed with plug means 239 (conveniently hung on a chain)so that the manometer will be disconnected when coupler 238 is attachedto connector 240 for sterilizing. One leg of the manometer is soconnected at coupler 238 through pressure line 244 and containselectrical contacts 246 which are electrically connected when mercuryrises to cover the contacts 246 at a negative pressure greater thanabout 150 mm./Hg to inactivate pumping means 214 and closesolenoid-operated control valve means 236 (if provided) and thereby stopdialysis. The other leg of the manometer is open to atmosphere.

FIG. 2 shows a preferred construction of manometer 220. The low pressureside of the manometer communicates with the connecting tube 244 throughan expansion chamber 248 within the upper end section of the manometer.This chamber is provided with two small ports 250 and 252 which open tothe manometer low pressure leg, and a bottom that slopes downwardlytoward the lower port 250. If the pressure in the waste conduit 212should suddenly fall below a predetermined level such that mercury inthe manometer low pressure leg would tend to surge through connectingtube 244 into waste conduit 212, the mercury would have to surge throughthe restricted ports 250 and 252, and then fill the expansion chamber248 before it could surge through the connecting conduit 244. Thus, as apractical matter, mercury will never escape the manometer to surgethrough the connecting conduit 244. Any mercury that reaches theexpansion chamber 248 will run back in the low pressure leg because ofthe chambers sloping bottom.

The system of this invention is particularly adapted for use as abedside dialysis station for use by a dialysis patient either at home orat a hospital or clinic. The station components can be convenientlyhoused in a cabinet such that the dialyzer supply conduit 206 and wasteconduit 212 extend therefrom and such that the flow-metering means 218,manometer 220, the indicator for temperature sensor 224, the adjusterfor heating means 222 and the flow control 216 are exposed for readingor adjusting. Such a cabinet could be attached to a wall next to apatients bed or supported on a pedestal or supported on a cabinet. It ispreferred that the bedside station be mounted at a higher elevation thanthe dialyzer so that gravity will produce a positive pressure on thedialysis solution inlet to the dialyzer.

It is believed that the invention will have been clearly understood fromthe foregoing detailed description of my now-preferred illustratedembodiment. Changes in the details of construction may be resorted towithout departing from the spirit of the invention and it is accordinglymy intention that no limitations be implied and that the hereto annexedclaims be given the broadest interpretation to which the employedlanguage fairly admits.

What is claimed is:

1. A dialysis control system which comprises a reservoir having an inletcommunicable with a dialysis solution supply means and an outlet, adialyzer supply conduit extending from the reservoir outlet andcommunicable with an inlet to a dialyzer; dialysis solution pumpingmeans having an inlet; a waste conduit extending from the pumping meansinlet and communicable with an outlet to the dialyzer; and sterilizingconnector means adapted to detachably couple said dialyzer supplyconduit to said waste conduit to bypass the dialyzer.

2. A dialysis control system which comprises a reservoir having an inletcommunicable with a dialysis solution supply means and an outlet; adialyzer supply conduit extending from the reservoir outlet andcommunicable with an outlet to a dialyzer; dialysis solution pumpingmeans having an inlet; a waste conduit extending from the pumping meansinlet and communicable with an outlet to the dialyzer; means for sensingdialysis solution pressure in said waste conduit upstream of the pumpingmeans inlet and for terminating dialysis solution flow through thedialyzer when the sensed pressure falls below a predetermined range;means for sensing dialysis solution temperature within said reservoirand for terminating dialysis solution flow to the dialyzer when thesensed temperature exceeds a predetermined range; and sterilizingconnector means adapted to detachably couple said dialyzer supplyconduit to said waste conduit to bypass the dialyzer and adapted toinactivate the pressure and temperature sensing means.

3. A system according to claim 2 including means for tempering dialysissolution within said reservoir within a predetermined temperature range,

4. A system according to claim 2 including control valve means forcontrolling dialysis solution flow from said reservoir through saiddialyzer supply conduit to a dialyzer.

5. A system according to claim 2 wherein said means for sensing dialysissolution pressure includes a U-type manometer having an expansionchamber interconnecting a low pressure outlet to a low pressure legthrough restricted openings, said expansion chamber having a bottomsloping downwardly toward one of said restricted openings.

6. A dialysis system including at least one dialysis station whichcomprises:

a dialyzer having an inlet and outlet for dialysate;

a reservoir tank having an inlet communicable with said dialysissolution reservoir means and having an outlet;

a dialyzer supply conduit extending from the reservoir tank outlet anddetachably connectable to the dialyzer inlet;

dialysis solution pumping means having an inlet and an outlet; a wasteconduit extending from the pumping means inlet and detachablyconnectable to the dialyzer outlet; first quick disconnect means fordetachably coupling said dialyzer supply conduit to said inlet;

second quick disconnect means for detachably coupling said waste conduitto said dialyzer outlet;

means for sensing the pressure of dialysis solution in said wasteconduit upstream of the dialysis solution pumping means inlet and forinactivating said dialysis solution pumping means when the sensedpressure falls below a predetermined range;

means for tempering dialysis solution within said reservoir tank withina predetermined temperature range;

means for sensing the temperature of the dialysis solution within saidreservoir tank and for inactivating said dialysis solution pumping meanswhen the sensed temperature exceeds a predetermined range;

and sterilizing connector means adapted to detachably couple saiddialyzer supply conduit to said waste conduit to bypass the dialyzer andadapted to inactivate the pressure and temperature sensing meanscontrols.

(References on following page) 5 6 References Cited OTHER REFERENCESUNITED STATES PATENTS Dr. Kolfis outline as presented by Dr. John Maherin Transactions American Society of Artificial Internal Or- 2 321 X 1 grrfm mf al gans, June 1963, pp. 368, 376, 377 and 380-382 relied on. .v I5 3,212,642 10/1965 210421 REUBEN FRIEDMAN, Primary Examiner 3,352,77011/1967 Austin et a1. 21023 JOHN ADEE, Assistant Exammer FOREIGN PATENTS847,182 2/1953 Germany.

250,526 8/1947 Switzerland. 10 211F321

